This does not sounds like a good solution to me at all.
Not only is it ethically questionable at best, but
technically unfeasible as well. Don't companies keep
a backup copy of the code somewhere? The only way to
truly ensure total "destruction" of the code is to
create some sort of self-propagating worm that would
hunt down and destroy all copies. I think anyone
who tried something like that would get the pants
sued off them quicker than you can say "dumb idea."